Static Cache

SpeedMate's static cache engine stores fully-rendered HTML pages on disk, serving them directly without initializing WordPress.

How It Works

Cache Flow Diagram

flowchart TB
    Start([HTTP Request]) --> AdvCache{advanced-cache.php}
    
    AdvCache --> CheckCache{Cache File<br/>Exists?}
    
    CheckCache -->|Yes| ValidCache{Cache<br/>Valid?}
    ValidCache -->|Yes| ServeCache[Serve Cached HTML]
    ValidCache -->|No TTL Expired| DeleteCache[Delete Expired Cache]
    
    CheckCache -->|No| InitWP[Initialize WordPress]
    DeleteCache --> InitWP
    
    InitWP --> GenerateHTML[Generate HTML Page]
    GenerateHTML --> Hooks{SpeedMate<br/>Hooks}
    
    Hooks --> OutputBuffer[Output Buffer Capture]
    OutputBuffer --> ProcessHTML[Process HTML]
    
    ProcessHTML --> ApplyOptimizations[Apply Optimizations:<br/>- Beast Mode JS<br/>- Critical CSS<br/>- Preload Hints<br/>- LCP Detection]
    
    ApplyOptimizations --> SaveCache[Save HTML to Cache]
    SaveCache --> SaveMeta[Save Metadata JSON]
    SaveMeta --> CompressGzip[Gzip Compression]
    
    CompressGzip --> ServeFresh[Serve Fresh HTML]
    ServeCache --> End([Response Sent])
    ServeFresh --> End
    
    style Start fill:#4A90E2
    style ServeCache fill:#7ED321
    style InitWP fill:#F5A623
    style SaveCache fill:#7ED321
    style End fill:#4A90E2

Cache Invalidation Flow

flowchart LR
    subgraph "Trigger Events"
        A1[Post Update]
        A2[Comment Added]
        A3[Theme Switch]
        A4[Plugin Update]
        A5[Manual Flush]
    end
    
    A1 & A2 & A3 & A4 & A5 --> B[WordPress Hook Fired]
    
    B --> C{Invalidation<br/>Strategy}
    
    C -->|Specific| D[Delete Related Cache]
    C -->|Cascade| E[Delete Related + Categories]
    C -->|Full| F[Flush All Cache]
    
    D --> G1[Delete Post Cache]
    G1 --> G2[Delete Homepage Cache]
    
    E --> H1[Delete Post Cache]
    H1 --> H2[Delete Category Caches]
    H2 --> H3[Delete Archive Caches]
    H3 --> H4[Delete Homepage Cache]
    
    F --> I[Delete All Cache Files]
    I --> J[Clear All Metadata]
    
    G2 & H4 & J --> K[Update Stats]
    K --> L([Cache Invalidated])
    
    style B fill:#F5A623
    style D fill:#7ED321
    style E fill:#F8E71C
    style F fill:#D0021B
    style L fill:#4A90E2

Detailed Process

1. First Request: WordPress generates HTML, SpeedMate saves it to disk
2. Subsequent Requests: advanced-cache.php serves cached HTML directly
3. Cache Invalidation: Automatic invalidation on post updates, comments, etc.
4. Cache Expiration: TTL-based expiration with configurable lifetime

Architecture (Legacy Text Diagram)

Request → advanced-cache.php → Cache Check
                                    ↓
                            Cache Hit? → Serve HTML (fast)
                                    ↓
                            Cache Miss → WordPress Init
                                              ↓
                                         Generate HTML
                                              ↓
                                         Save to Cache
                                              ↓
                                         Serve HTML

Cache Storage

Cache files are stored in wp-content/cache/speedmate/:

cache/speedmate/
├── html/
│   ├── example.com/
│   │   ├── index.html
│   │   ├── about.html
│   │   └── blog/
│   │       └── post-name.html
│   └── example.com.meta/
│       ├── index.json
│       └── about.json
└── fragments/
    └── dynamic-widgets/

Cache File Structure

HTML Files: Gzip-compressed HTML content Meta Files: JSON metadata with:

• Creation timestamp
• Expiration timestamp
• Request headers
• User agent
• Cache key

Cache Keys

Cache keys are generated based on:

• Request URI
• Query string parameters
• User agent (mobile/desktop)
• Cookies (logged-in users)
• Custom headers

Example cache key:

md5(uri + query_string + user_agent + cookies) = abc123def456

Cache Invalidation

Automatic Invalidation

SpeedMate automatically invalidates cache when:

• Post/page published or updated
• Comment added/modified
• Theme switched
• Plugin activated/deactivated
• Settings changed

Manual Invalidation

# Flush all cache
wp speedmate flush

# Flush specific pattern
wp speedmate flush --pattern=/blog/*

# Via REST API
curl -X POST /wp-json/speedmate/v1/cache/flush \
  -H "X-WP-Nonce: $NONCE"

Programmatic Invalidation

// Flush single URL
\SpeedMate\Cache\StaticCache::instance()->flush_url('https://site.com/page');

// Flush by pattern
\SpeedMate\Cache\StaticCache::instance()->flush_pattern('/blog/*');

// Flush all
\SpeedMate\Cache\StaticCache::instance()->flush_all();

Configuration

Basic Settings

update_option('speedmate_settings', [
    'mode' => 'static',        // Enable static cache
    'cache_ttl' => 3600,       // 1 hour lifetime
    'gzip_enabled' => true,    // Enable gzip compression
    'cache_logged_in' => false // Don't cache logged-in users
]);

Advanced Options

// Exclude specific URLs from cache
add_filter('speedmate_cache_exclude', function($exclude) {
    $exclude[] = '/checkout/*';
    $exclude[] = '/my-account/*';
    return $exclude;
});

// Customize cache key
add_filter('speedmate_cache_key', function($key, $url) {
    // Add custom parameter to cache key
    if (isset($_GET['custom'])) {
        $key .= '_custom_' . $_GET['custom'];
    }
    return $key;
}, 10, 2);

// Modify cached HTML before serving
add_filter('speedmate_cached_html', function($html) {
    // Inject timestamp
    $html = str_replace(
        '</body>',
        '<!-- Cached: ' . date('Y-m-d H:i:s') . ' --></body>',
        $html
    );
    return $html;
});

Cache Headers

SpeedMate adds custom headers to identify cache status:

X-Cache: HIT              # Served from cache
X-Cache: MISS             # Generated by WordPress
X-Cache-Time: 0.002s      # Time to serve
X-Cache-Age: 245          # Age in seconds

Performance Impact

Without Cache:

• Average response time: 500-1000ms
• Database queries: 50-100 per request
• Memory usage: 50-100MB

With Static Cache:

• Average response time: 2-5ms
• Database queries: 0
• Memory usage: < 5MB

Best Practices

1. Set Appropriate TTL: Balance freshness vs performance
2. Monitor Hit Rate: Aim for 90%+ hit rate
3. Use Cache Warming: Pre-cache popular pages
4. Exclude Dynamic Content: Don't cache user-specific pages
5. Enable Gzip: Reduce bandwidth usage

Troubleshooting

Cache Not Working

# Check cache directory permissions
ls -la wp-content/cache/speedmate/

# Verify advanced-cache.php exists
ls -la wp-content/advanced-cache.php

# Check WP_CACHE constant
wp config get WP_CACHE

Low Hit Rate

1. Check exclusion rules
2. Verify TTL is not too short
3. Review cache invalidation triggers
4. Check for dynamic content in templates

Cache Size Growing

# Check cache size
du -sh wp-content/cache/speedmate/

# Run garbage collection
wp speedmate gc

# Set up cron for regular cleanup
0 3 * * * wp speedmate gc --path=/var/www/html

Next Steps

• Enable Beast Mode
• Configure Cache Control
• Traffic Warmer